CTM90620 | Corporation tax self-assessment (CTSA): Claims and elections: Categories
From HM Revenue & Customs · Company Taxation Manual
Claims and elections under CTSA fall into three categories.
Claims that affect only one accounting period, (FA98/SCH18/PARA57).
Claims that affect more than one accounting period, (FA98/SCH18/PARA58).
All other claims and elections, (FA98/SCH18/PARA59).